The present invention relates to vehicles used to transport loads (hereafter, "transport vehicles") that are guided by guide rails and guide device for such vehicles.
Transport vehicles and their associated guide device are used in automated warehouses and various types of plants. There are various types of transport vehicles aside from those guided by guide rails. For example, some types of transport vehicles use magnetic induction via magnetic tape to define a guide path. Another example, is the widely-used forklift.
These vehicles have their associated advantages and drawbacks. Vehicles that are guided by guide rails, however, have major advantages not available in the other types of vehicles. These advantages include the capability of safely moving different types of loads, which is made possible by the smoothness of operations, as well as the capability of improved efficiency resulting from increased driving speed.
On the other hand, these vehicles require the installation of guide rails along the travel path, and this is one factor that has prevented more widespread application of these vehicles.
It is possible to embed the guide rails along the travel path, but the task of laying the guide rails is involved and expensive. As a result, guide rails are more frequently placed directly on the floor. In such above-ground rail installations, however, the rail interferes with other traffic and operations. Also, in conventional transport vehicles, the load is carried over the rail so that the guide rail projects away from the side of the carrying platform. This configuration presents problems where a standard forklift must be used to transport a load to and from the transport vehicle next to the travel path of the transport vehicle, (including, of course, when the transport vehicle breaks down). In such conventional transport vehicles, the guide rail projecting adjacent the load carrying area interferes with the movement of the forklift (or other transporter) potentially preventing it from getting close to the load carrying area.